Currently, the characterization of vacuum ultraviolet (VUV) light sources involves several technical problems. The main problem is the need to simultaneously satisfy the tight space restrictions for the setup while preserving the functionality of each mode and the convenient switching capability between different operating modes. Current practice always involves major changes to the light source assembly in order to switch between characterizing the VUV beam and using the VUV beam for its intended purpose. There is no device available that can readily switch between a spectrometer and beam profiling mode in the VUV photon energy regime “at the push of a button”. These two characteristics of the VUV photon beam usually have to be measured by two independent devices or several components of the experimental setup have to be altered one-by-one in order to switch between the different modes. There is no device available that fulfill these needs.